hdu2087 剪花布条(kmp)

思路：纯kmp

#include <cstdio>
#include <algorithm>
#include <iostream>
#include <vector>
#include <cstring>
#define mem(a,b) memset(a,b,sizeof(a))

using namespace std;
string a[1005];
int dir[4][2] = {0,1,0,-1,1,0,-1,0};
int countt,vis[1005][1005],num[1005][1005],ans[1005],sum;
 void getnext(char *p,int next[])
 {
     int len = strlen(p);
     next[0] = -1;
     int k = -1;
     int j = 0;
     while(j < len -1){
        if(k == -1 || p[j] == p[k])
        {
            k++;
            j++;
            if(p[j] != p[k])
            next[j] = k;
            else next[j] = next[k];
        }
        else
            k = next[k];
     }
 }
 int main()
{
    char s[1005],p[1005];
    int next[1005];
    while(cin >> s){
        if(s[0] == '#') break;
        cin >> p;
        getnext(p,next);
        int len = strlen(p),len2 = strlen(s);
      // for(int i=0; i<=len-1;i++) cout << next[i] << endl;
      int j = 0,ans = 0;
      for(int i = 0;i < len2;)
      {
          if(s[i] == p[j]) {
            i++;
            j++;
          }
          else {
            while(j!=-1 && s[i] != p[j])
            j = next[j];
            i++;
            j++;
          }
          if(j == len)
          {
              j = 0;
              ans++;
          }
      }

      cout << ans << endl;
    }
    return 0;
}